[Wien] linearization energy in *.in1

[Peter Blaha]

Your results nicely prove that basically it does NOT matter what state
(semicore or valence) you describe as LO. Both "basis sets" are almost
equally good.

In the input generation we adopt the rule that when the semicore state is
really low in energy, it will be described as LO, if it is not so low
(only at -1 or -2 Ry) it may need the "full flexibility" of APW+lo. In this
case the "valence state" (eg. N "3s") is less important and described
by a LO.

Regards

Hong Jiang schrieb:
> Dear Professor Blaha and wien2k users,
> Recently I found something strange (at least for me). When doing LDA 
> calculations for LaN with RMT(La)=2.5 a.u., RMT(N) = 2.0 au, and RKMAX=9.0,
> the linearization energy setup in the LaN.in1 generated automatically by 
> init_lapw is like this
> 
> WFFIL        (WFPRI, SUPWF)
>   9.00       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>   0.30    5  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
> APW/LAPW)
>  0   -2.57      0.010 CONT 1
>  0    0.30      0.000 CONT 1
>  1   -1.30      0.010 CONT 1
>  1    0.30      0.000 CONT 1
>  2    0.30      0.010 CONT 1
>   0.30    3  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
> APW/LAPW)
>  0   -1.14      0.010 CONT 1
>  0    0.30      0.000 CONT 1
>  1    0.30      0.000 CONT 1
> K-VECTORS FROM UNIT:4   -9.0       2.0      emin/emax window
> 
> So according to this *.in1, the l=0 orbital has a APW+lo at about -2.57 
> Ry, and has a local orbital at 0.3 Ry.
> But this seems to be in contraction with  the standard treatments.  
> According to my understanding about the (L)APW+lo method, the "standard" 
> treatment is to
> set a APW+lo with  a linear energy close to the Fermi level, 0.3 Ry;
> if there there is a lower semi-core state with same l value, e.g. 5s 
> orbital for La, one adds a local orbital with an energy close to that of 
> the semi-core state. Similar things happen also for l=1 of La and l=0 of 
> N  orbitals.
> I changed the configuration in LaN.in1 and repeat the SCF calculation,
> 
> WFFIL        (WFPRI, SUPWF)
>   9.00       10    4 (R-MT*K-MAX; MAX L IN WF, V-NMT
>   0.30    6  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
> APW/LAPW)
>  0    0.30      0.000 CONT 1
>  0   -2.57      0.010 CONT 1
>  1    0.30      0.000 CONT 1
>  1   -1.30      0.010 CONT 1
>  2    0.30      0.010 CONT 1
>  3    0.30      0.010 CONT 1
>   0.30    3  0      (GLOBAL E-PARAMETER WITH n OTHER CHOICES, global 
> APW/LAPW)
>  0    0.30      0.000 CONT 1
>  0   -1.14      0.010 CONT 1
>  1    0.30      0.000 CONT 1
> K-VECTORS FROM UNIT:4   -9.0       2.0      emin/emax window
> 
> The converged total energy from these two different *.in1 files are 
> actually quite small, -17091.517012 Ry. vs -17091.516955 Ry. 
> 
> My questions are:  What is this difference for? I mean, why is that in 
> some cases the lower energy state is treated as "LO", but in other cases 
> the higher energy state is treated as "LO"?  Are they equivalent?  If 
> not, what is the criterion to choose one of them?
> Thank you very much!
> 
>   Hong
> 
> _______________________________________________
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> Wien at zeus.theochem.tuwien.ac.at
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-- 

                                       P.Blaha
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Peter BLAHA, Inst.f. Materials Chemistry, TU Vienna, A-1060 Vienna
Phone: +43-1-58801-15671             FAX: +43-1-58801-15698
Email: blaha at theochem.tuwien.ac.at    WWW: http://info.tuwien.ac.at/theochem/
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